Electronic Components Datasheet Search |
|
HT48E70 Datasheet(PDF) 9 Page - Holtek Semiconductor Inc |
|
HT48E70 Datasheet(HTML) 9 Page - Holtek Semiconductor Inc |
9 / 44 page HT48E70 Rev. 1.00 9 September 16, 2005 complete the operation. These areas may function as normal program memory depending upon the require- ments. Stack Register - STACK This is a special part of the memory which is used to save the contents of the Program Counter only. The stack is organized into 16 levels and is neither part of the data nor part of the program space, and is neither read- able nor writable. The activated level is indexed by the stack pointer (SP) and is neither readable nor writeable. At a subroutine call or interrupt acknowledge signal, the contents of the program counter are pushed onto the stack. At the end of a subroutine or an interrupt routine, signaled by a return instruction (RET or RETI), the pro- gram counter is restored to its previous value from the stack. After a chip reset, the SP will point to the top of the stack. If the stack is full and a non-masked interrupt takes place, the interrupt request flag will be recorded but the acknowledge signal will be inhibited. When the stack pointer is decremented (by RET or RETI), the interrupt will be serviced. This feature prevents stack overflow al- lowing the programmer to use the structure more easily. In a similar case, if the stack is full and a ²CALL² is sub- sequently executed, stack overflow occurs and the first entry will be lost (only the most recent 16 return ad- dresses are stored). Data Memory - RAM The data memory has a capacity of 256 ´8 bits and is divided into two functional groups: special function reg- isters and general purpose data memory (224 ´8). Most are read/write, but some are read only. The special function registers include the indirect ad- dressing registers (R0;00H, R1;02H), the Bank Pointer (BP;04H), timer/event 0 higher order byte register (TMR0H;0CH), Timer/Event Counter 0 lower order byte register (TMR0L; 0DH) Timer/Event Counter 0 control register (TMR0C;0EH), Timer/Event Counter 1 higher order byte register (TMR1H;0FH), Timer/Event Counter 1 lower order byte register (TMR1L;10H), Timer/Event Counter 1 control register (TMR1C;11H), program coun- ter lower-order byte register (PCL;06H), memory pointer registers (MP0;01H, MP1;03H), accumulator (ACC;05H), table pointer (TBLP;07H), table higher-order byte register (TBLH;08H), status register (STATUS;0AH), interrupt control register (INTC;0BH), Watchdog Timer option setting register (WDTS;09H), I/O registers (PA;12H, PB;14H, PC;16H, PD;18H, PE;1AH, PF;1CH, PG;1EH) and I/O control registers (PAC;13H, PBC;15H, PCC;17H, PDC;19H, PEC;1BH, PFC;1DH, PGC;1FH). The general purpose data mem- ory, addressed from 20H to FFH, is used for data and control information under instruction commands. All of the data memory areas can handle arithmetic, logic, increment, decrement and rotate operations di- rectly. Except for some dedicated bits, each bit in the data memory can be set and reset by ²SET [m].i² and ²CLR [m].i². They are also indirectly accessible through memory pointer registers (MP0 or MP1). The control register of the EEPROM data memory is located at [40H] in Bank 1. Indirect Addressing Register Location 00H and 02H are indirect addressing registers that are not physically implemented. Any read/write op- eration of [00H] ([02H]) will access data memory pointed to by MP0 (MP1). Reading location 00H (02H) itself indi- rectly will return the result 00H. Writing indirectly results in no operation. G e n e r a l P u r p o s e D A T A M E M O R Y ( 2 2 4 B y t e s ) S p e c i a l P u r p o s e D A T A M E M O R Y 0 0 H 0 1 H 0 2 H 0 3 H 0 4 H 0 5 H 0 6 H 0 7 H 0 8 H 0 9 H 0 A H 0 B H 0 C H 0 D H 0 E H 0 F H 1 0 H 1 1 H 1 2 H 1 3 H 1 4 H 1 5 H 1 6 H 1 7 H 1 8 H 1 9 H 1 A H 1 B H 1 C H 1 D H 1 E H 1 F H F F H : U n u s e d R e a d a s " 0 0 " 2 0 H I n d i r e c t A d d r e s s i n g R e g i s t e r 0 M P 0 I n d i r e c t A d d r e s s i n g R e g i s t e r 1 M P 1 B P A C C P C L T B L P T B L H W D T S S T A T U S I N T C T M R 0 H T M R 0 L T M R 0 C T M R 1 H T M R 1 L T M R 1 C P A P A C P B P B C P C P C C P D P D C P E P E C P F P F C P G P G C RAM Mapping |
Similar Part No. - HT48E70 |
|
Similar Description - HT48E70 |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.NET |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |